View Full Version : Print developer dilution

Harlan Chapman
22-Nov-2011, 23:35
The Dektol package recommends a 1:2 dilution of stock to working strength. Bruce Barnbaum, in his book "The Art of Photography" suggests diluting Dektol 1:5. Aside from slowing down your print development would there be any other effects from using Dektol more dilute than 1:2?

23-Nov-2011, 01:25
Why dont you try and see what happen ??

Greg Blank
23-Nov-2011, 03:17
I agree you should try it, in general though a loss of contrast, which in some cases can be appropriate.

23-Nov-2011, 06:00
I have not made any measurements of the changes, nor do anything above grade 4.

My result with Ilford MG RC WT is that it just takes a bit longer to develop. With the arista private reserve paper, it seemed to prefer a stronger developer than overdiluted or worn out dektol. Haven't tried graded paper in weaker dektol yet.

Dektol is cheap enough to use at 1:2. Kinda laborious to mix though as it seems to dissolve slow.

23-Nov-2011, 08:06
I use Dektol 1:3 for slightly reduced contrast with Oriental MG FB...seems (to me) to give a little more separation in the shadows - and softens the highlights a bit...especially with lower grades or if the image will be toned...

Dektol 1:4 I've used for paper negatives with Ilford MG RC - seems to cut the contrast just enough to make printing easier...though I keep the lighting pretty flat on exposure...

I've used higher dilutions (1:10) as a water bath for controlling highlights, and sometimes heated - but I really couldn't say it works any better than plain water, difference is so slight...

Most of the time recently I start with 1:3 dilution....only using 1:2 if I find the print needs a little extra...


Andrew O'Neill
23-Nov-2011, 08:43
With amble exposure, one can obtain more development in the highlights. This is great when you have a very contrasty negative and highlights are very important. With the extended development time, you run the risk of safe light fogging.

23-Nov-2011, 14:56
I've never seen a difference other than faster development time.

Harlan Chapman
26-Nov-2011, 07:40
Thank you all for your help here.
In manufacturer's instructions on using developers I've read that higher dilution can effect a lower contrast print but without any more information than that. I've also read in Lambrecht's "Way Beyond Monochrome", in the chapter on factorial print development, that dilution makes no difference in contrast when the print is developed to a standardized completion point. Their standard completion point is based on a multiple of the time when mid-tones are first observed to appear in the print, typically 6 to 8X. Lambrecht makes the case that this print development timing method compensates for situations of different developer temperature, exhaustion, and dilution so you can get more consistent results.
So I was wondering what was really up when Barnbaum suggested using more dilute developer. Surely not just to waste his valuable time. Maybe it just gives you more flexibility to work with if you want to pull a print before it is complete and therefore has lower contrast?
I was hoping to avoid spending more darkroom time printing the dreaded step wedge to sort this out. Looks like the answer isn't clear cut and wise Payral is probably right, I'll just have to try it and see for myself.

26-Nov-2011, 10:11
The dilution along with the exposure and development time can have a very marked effect on the contrast and tones particulary with regard to image colour with chlorobromide papers.

So some of use use dilution and in=creased exposure to get greater warmth from our papers.

There's also two types of Dektol, the original powder version, D72, an MQ based developer and Liquid Dektol which is a PQ developer soldo as Polymax in some countries.


Alan Curtis
27-Nov-2011, 13:17
I use a 1:5 dilution of Dektol to water and develop for 4 minutes. My darkroom water temp. is about 78 most of the year, using a Zone VI compensating timer my real time is about 2 minutes at that temp. From what I've read Bruce Barnbaums idea is that at 2 minutes of development a print pulled out 10 seconds either side of that time could be very different from a 2 min. print. By diluting the developer and extending the time that 10 seconds isn't significant.
My reason is strictly because of water temperature.